Smart Enhancement of TCP Performance Over Lossy WLAN Channels Through the Combined Use of Link Layer Techniques

This paper shows an important enhancement of TCP behavior over the IEEE 802.11b Wireless Local Area Network (WLAN) if a combination of a Forward Error Correction (FEC) scheme and a Snoop agent is added to the idle Repeat reQuest (RQ) mechanism inherently used by such technology. The FEC scheme has been improved with some smart cross-layer optimizations, and its operation adapts to the channel conditions. Besides, the aim of the Snoop agent is to back up the FEC, overcoming the deficiencies of its adaptation, which are mainly due to the high variability of the channel inside a typical office environment. A complete experimental approach has been followed, and exhaustive measurement campaigns have been carried out over a real platform to derive a large number of performance parameters. Both methods have been implemented as modules belonging to a generic layer-two Performance Enhancing Proxy (PEP).